Breechblock for firearms



March 7, 1950 A. H. TOMPKINS BREECHBLOCK FOR FIREARMS Original Filed Feb. 13, 1946 2 Sheets-Sheet 1 INVENTOR 14185177 1?: EMPK/Ms ATTORNEYS March 7,1950 A. H TOMPKINS 2,500,103

BREECHBLOCK FOR FIREARMS Original Filed Feb. 13, 1946 2 Sheets-Sheet 2 INVENTOR A: affirfl ZZMPK/Ms (36% sw aa v ATTORNEYS Patented Mar. 7, 1950 F F lCE :BREECHBLOCK FOR FIREARMS Albert H. Tompkins, Springfield, Mass.

Original application February 13, 194.6, Serial No. 647,318. Divided and this application January 19, 1948, Serial No.3,120

3 Claims. (ore-s6) This invention relates to firearms, and "more particularly to an improved breechblock which .greatly increases the strength of the firearm.

Other and further objects will appear "from the following description and claims.

In the accompanying drawings: Fig. l'is a side elevational viewof'an arm em- 'bodying the invention;

Fig. 2 is a fragmentary side elevation with the breechblock open and'the hammer cocked, parts being broken away to .show features of construction;

Fig. 3 is a similar view with thebreechblock closed;

Fig. 4 is a fragmentary'top plan view with the breechblock about to be opened;

Fig. 5 shows in median section the first stage in the opening of the breechblock;

Fig. Bisa side elevation, partly broken away, of

the same position as .Fig. 5';

Fig. 7 is a side elevation showing the first stage in closing the breechblock;

Fig. 8'is a section substantially online 8-8 of Fig. 9;

Fig. '9 is a 'section'substantially on'line 9-9 of Fig. 8; and

Fig. 10 is a section substantially on line l0l0 of Fig. 3.

The improved breechblock mechanism isshown as applied for illustration to asingle shot target pistol, but it is obvious that various features of the mechanism can be used in other settings.

The main frame I which carries 'the operating parts of the arm is secured in any usual or desired way in a stock 2. This stock preferably extends along the barrel 3 and as shown in Fig. l

it can be swung upwardly to expose the barrel chamber. A firing pin H is slidable in a hole [2 in the block 8 directed so that the point l3 of the firing pin will strike the primer of the cartridge. A groove I4 in the firing pin receives the reduced end !5 of a set screw l6 threaded into the block 8, so that the firing pin may have the free motion needed for its operation but cannot fall out when the breechblock is open.

The rear of the side walls of the block 8 are formed with a vertical slideway such as vertical drawn positively from its firing position.

grooves I l for the reception of a T-slot l8 in the finger piece 9 which in this way is made vertically slidable. One of the ribs 29 formed by the grooves I7 is cut away at 2| (Figs. 4, 6, 9 and 10') to receive freely the turned down end 22 of a set screw 23 secured in the finger piece '9. The finger piece is thus permitted a limited vertical sliding motion relative to the block 8. Normally the finger piece is held down on the same level as the block 8 as by a bent spring 24 (Figs. 8 and 9) held by a screw 25 in a slot 26 formed in the block and having one end projecting into a recess 2! in the finger piece.

The frame I to the rear of the breechblock is formed with two vertical surfaces 28 and 29 separated by a horizontal step 39. The frame is cut out with a central slot 3| to receive the hammer 32, there being a corresponding recess 33 in the finger piece 9 separated on a slant line '34 from a narrower recess 35 embracing slabbed oil portions 36 of the firing pin H just forward of its head 31. The front of this head is cut away at 38 to mate with the slanting surface 34, so that, as the finger piece is in raised position relative to the block, the firing pin will be with- The hammer recess 3! does not extend to the top of the frame, leaving a cross bridge 39 which may serve as an abutment against which a shoulder 40 on the hammer may strike if the hammer is released with no cartridge in the chamber, this preventing crystallization of the firing pin head if it is desired to practice with the arm in this condition.

The finger piece 9 acts both as a lock for the breechblock and as an extension of it to "the abutment surfaces 28 and 2d of the frame when .the block is in its normal position of Fig. 3. For

this purpose the finger piece has an upper vertical surface 4! separated by a shoulder 42 from a lower vertical surface. Referring to Fig. 3 it will be noted that the upper surface 4| is shorter than its mating surface 28 and that the lower surface 43 is longer than its mating surface 29 so that a substantial space is left between the shoulders 30 and 42. When the breechblock is in closed position these pairs of surfaces act as abutments which tra smit the force of the explosion to the name. To disengage the breechblock the finger piece 9 is grasped and drawn upwardly. Initially both pairs of surfaces prevent an swinging movement of the breechblock, as any swinging movement would press the abut merits more tightly together on account of the position of the hinge ID. The finger piece thus moves vertically and against its spring. When the finger piece has moved upwardly so that surface M moves beyond the top of surface 28 and surface 43 moves beyond shoulder 30 swinging movement of the breechblock is permitted and the block 8 will catch up with the finger piece on account of its spring connection. In order to avoid binding the lower pair of abutting surfaces are preferably made of slightly less height than the upper pair; as the upper surface 4| is, by reason of its horizontal alignment with pivot H3, moving most parallel to the surface 28 at the instant of disengagement.

Locking of the breechlock is accomplished by pressing downwardly on the block 8 rather than on the finger piece which, as shown in Fig. 7, intially comes to a position against shoulder 30 where it is incapable of downward movement. The block is, however, free to move downwardly on account of the spring connection and assumes more and more a horizontal position with the finger piece remaining elevated but tending towards the position of Fig. 5. As soon as this position is reached the lower surface 43 clears the shoulder 38 and the finger piece is shot downwardly by the spring. The breechblock is now locked and can be freed only by pulling upwardly on the finger piece.

The hammer 32 is actuated from a trigger 44 by any suitable mechanism such as that shown in United States Patent 2,455,830, issued to applicant December '7, 1948, on application Serial No. 647,318, filed February 13, 1946, of which the present application is a division.

What I claim is:

1. In a firearm having a chamber. a frame formed at the rear of the chamber with a recess having its forward end wall substantially vertical and its rear end formed with two stepped vertical surfaces the upper of which is further from said forward end wall than the lower, a breech block hinged at its forward end adjacent the upper end of the forward end wall of the recess and having a vertical slideway adjacent its rear end, a finger piece vertically slidable in said slideway and having its rear end formed with two stepped vertical surfaces to engage the stepped surfaces of the recess, and means for limiting the vertical movement of the finger piece relative to the block, the extent of the lower vertical surface of the recess and of the upper vertical surface on the finger piece being such that when the finger piece is in raised position relative to the block the finger piece and block are freed for pivotal movement about said pivot.

2. In a firearm having a chamber, a frame formed at the rear of the chamber with a recess having its forward end wall substantially vertical and its rear end formed with two stepped vertical surfaces the upper of which is further from said forward end wall than the lower, a breech block hinged at its forward end adjacent the upper end of the forward wall of the recess and having a vertical slideway adjacent its rear end, a finger piece vertically slidable in said slideway and having its rear end formed with two stepped vertical surfaces to engage the stepped surfaces of the recess, means for limiting the vertical movement of the finger piece relative to the block, and spring means between the block and finger piece stressed to shift the latter into its lower position relative to the block, the extent of the lower vertical surface of the recess and of the upper vertical surface on the finger piece being such that when the finger piece is in raised position relative to the block the finger piece and block are freed for pivotal movement about said pivot.

3. In a firearm having a chamber, a frame formed at the rear of the chamber with a recess having its forward end wall substantially vertical and its rear end formed with two stepped Vertical surfaces, the upper of which is further from said forward end wall than the lower, a breechblock hinged at its forward end adjacent the upper end of the forward wall of the recess and having a vertical slideway adjacent its rear end, a finger piece vertically slidable in said slideway and having its rear end formed with two stepped vertical surfaces to engage the stepped surfaces of the recess, means for limiting the vertical movement of the finger piece relative to the block, a firing pin extending through the block and mounted for substantially horizontal sliding movement therein, a vertical slot in the finger piece through which the rear portion of the firing pin extends, a head formed on the rear end of the firing pin, the forward face of the head engagin the rear face of the finger piece along the portions adjacent said slot, said portions being inclined rearwardly and downwardly whereby the firing pin is moved rearwardly in the breechblock when the finger piece is moved upwardly in said slideway, the extent of said lower vertical surface of the recess and of said upper vertical surface on the finger piece being such that when the finger piece is in raised position relative to the block the finger piece and block are freed for pivotal movement about said pivot.

ALBERT H. TOMPKINS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 52,887 Roberts Feb. 2'7, 1866 61 082 Milbank Jan. 8, 1867 88 531 Varney Mar. 30, 1869 101,418 Berdan Apr. 15, 1870 

